Apparatus for obtaining maximum depth of flash of oils and the like



M Feb. 24; 1959 D. M. LITTLE 2,875,139 APPARATUS FOR OBTAINING MAXIMUMDEPTH OF FLASH OF OILS AND THE LIKE 2 Sheets-Sheet 1 Filed May 22. 1953FIG. 2

INVENTOR. D. M. LITTLE no.4 y

Feb. 24, 1959 TLE 2,875,139

I D. M. LIT APPARATUS FOR OBTAINING MAXIMUM DEPTH OF FL'A'SH OF OILS ANDTHE LIKE Filed May 22, 1953 2 Sheets-Sheet 2 48 5| sl 7 4a 40' 46 FEED50 4| FEED RESIDU'E DISTILLATE RESIDUE FIG. 6

CONDE'NSATE DRAWOFF CONDENSING SPRAY 1 \RESlDUE DRAWOFF INVENTOR. FEEDD.M.L|TTLE FIG. 8 4

' M *A TORN S United States Patent APPARATUS. FOR OBTAINING MAXIMUMDEPTH 0F FLASHOF OILS AND THE LIKE DonaldM. Little,.Bartlesvilie, Okla,assignor to Phillips Petroleum Company, a corporation of DelawareApplication May22, 1953,,Serial No. 356,848

11 Claims. (Cl. 202-185) -..This invention relatesto theitlashing andrecovery of vapors fromfiuids. In one aspect of the invention it:relates to an apparatus in which no transverseimpediment of anysignificant characteris present in the line of flow of vapors resultingfrom a flashing of vapors from a liquid. In still another aspect of theinvention as .it relatesqto an apparatus embodiment especially suited tothe flashing of vaporsfrom mineral oils, there vapors from liquids, e.g., distillate from mineral oils,

obtaining a liquid residue, is known to this inventor. Such vesselscomprise ahorlzontally disposed elongated shellinto one end of which isfed a stream of oil preheated to a desired temperature. The oil,uponentering the vessel, undergoes flashing liberating vapors which arepassed through bafiles and/or sprays in order to obtain a cleandistillate vapor at or near the other end of the vessel in which endthere are provided condensing sprays to cause condensation of thedistillate vapors. Distillate is Withdrawn from the vessel at said otherend thereof. In order to avoid contamination of condensed distillatewithresidual o-ilwhich accumulates along the bottom of the vessel thereisuprovided adam across the bottom of the vessel substantially at rightangles to its longitudinal axisto cause'accumulation between said damand the pointer? entry of the feed of said. residual oil.

Means are provided for withdrawing the residual oil -asit accumulates.Such vesselsare advantageously prowvided with vacuum jets and conduitsleading tosaid jets can be provided withoguard chambers, etc. Number188,604 filed OctoberS, 1950, now abandoned, by V..C...Cavin et al.there are described and claimed amethod and" apparatus inwhicha materialto be distilled is fed into andfiashed. atone endof an'elongated chamberor vessel andtreate'dwith a clean-up spray -which 'isiat substantially.the temperature of the vapors "to. cause removal. fromisaid vapors ofentrained droplets of residualmaterial. The vapors are then: treatedwith a condensing spray to cause. condensation of a distillate "whichisrecovered. :In'tSeiialNumber. 241,183" filed Ad -gustll9, 1951,nowabandoned, by Paul M. Waddill there In Serial are describedandclaimed, J additionally, a method and apparatus in which 31.two-stage separation ofvapors from materials or :oilscto be flashedispracticed by causing .ma'terials fedto the ends of a vessel to beflashed toward a mid-portion thereof and condensed at. said mid-portionto which :a source of vacuum can be :applied. rspecific embodiment ftheredescribed, residual oil from oneuendof the vessel. is. used asfeedfor the other end i of .said vessel, thusflin effect accomplishing atwo-stage wflashing 'or distillation. In: still another. embodimentder;.scr'ibed, tthezrmaterialltbxbeflashd.is fedlto one endlof Ina avessel and vapors :are condensed and removed downstream from said endand recovered as distillate product. The residual oil resulting fromsaidflashing is passed to another vessel for flashing at a reduced pressureby virtue of a pipe connection of said vessel with said first-mentionedvessel at a point down-streamfrom said firstrnentioned end of saidmentioned vessel.

in the said methods and apparatus known to me there can be employedbafiies'which are placed substantially transversely of the flow of thegenerated vapors. Obviously, whenever a flowing fluid must pass througha bafiie, there is encountered a pressure drop and, there fore, upstreamof said baflie the flashing pressure will be higher than it would hewere there no baflle.

I have nowfound that it is possibleto eliminate use of all bafiies whichare transversely placed in respect of vapor flow, yet I am able toremove from vapors generated upon flashing a material to be separatedinto a vapor and a residual liquid any entrained droplets of residualliquid.

According to the invention, there is provided an 'apparatus in which thevapors generated by flashing a material which is to be separated intovapors and a residual liquid are caused to be turned through an angle orto pass around at least one end of a partition which is longitudinallydisposed within a substantially horizontally placed elongated vessel. p

in passing around the end of the partition, the vapors are turnedthrough anangle of aboutQOdegrees, preferably through about 180 degrees.The momentum of any entrained residual liquid causes said liquid to tendto continue in the same direction and sense in which the vapors weretravelling before the vapors were turned through said angle. This causesimpingement of the said entrained liquid or droplets or particles uponthe inside of the end wall of the vessel at which the said particlescoalesce and flow to the bottom of said vessel from which said entrainedmaterial or liquid can be withdrawn.

An important feature of the invention resides in the arrangement of asurfacelfor impingement of the entrained liquid such that there ispresent on said surface no substantial quantity. of liquid, thusavoiding the. picking up of such liquid by the vapors Which,of course,

would defeat. one of the objects of the invention, namely, the removalof entrained liquid. Thus, according to this invention, the surface uponwhich or againstwhich the entrained droplets are caused to impinge issubstantially vertically disposed to cause immediate run-down of anyremainder which otherwise would tend to collect thereon. Furthermore,the surface against which the entrained droplets are caused to impingecan be machined in various ways to cause the collected entrainedliquidto resist separation-from said surface owing to frictional or othercontact of the vaporstherewith atsaid surface.

In order to more fully set forth and to more fully describe theapparatusaccording to this invention, reference is made to the drawings in whichFigure l is a view from above of a horizontal cross-section takenlongitudinally along the axis of a substantially horizontal vessel intowhich the feed or material to be fiashed is fed at one side of avertical solid partition plate and vapors condensed and removed on theother side of said plate as more fully described below. Figure 2 is avertical crosssection at degrees, along line 22, to the longitudinalaxis of the embodiment of the invention'shown in Figure 1. Figure 3 is avertically taken longitudinal cross-section passing through the axis ofanother vessel according to the invention showing the feed inlet andresidue draw-off side of a partition member. Figure 4 shows the vaporcondensing and removalside of the vessel of Figure 3. Figured is a viewfrom'above of a horizontally taken longitudinal cross-section. throughthe axis of the vessel of Figure 3. Figure 6 is a vertically takenlongitudinal cross-section passing through the axis of still anothervessel according to the invention showing feed inlets arranged'below apartition around the ends and up over which vapors flashed below saidpartition are passed and into which said vapors are condensed and fromwhich distillate liquid is withdrawn. Figure 7 is a verticalcrosssection taken at right angles to and at the midpoint of thelongitudinal axis of the vessel of Figure 6. Figure 8 is a top view incross-section of an elementary embodiment of the invention in which thevapors are turned through an angle of the order of 90 degrees.

DESCRIPTION OF FIGURE 1 In Figure 1 is shown horizontally disposedvessel 1 provided with vertical solid partition plate 2 which extendsfrom the right-hand end of vessel 1 along its longitudinal axis to apoint near the other end of the vessel such that the free area oropening between the end of the partition and said other end of thevessel is substantially equivalent to the cross-sectional area betweenpartition 2 and the sides of the vessel. As shown, partition 2 is placedso that it passes through the longitudinal axis of the vessel. It isclear that partition 2 may be so positioned that it will pass to oneside or the other of said longitudinal axis. Material or liquid to beflashed ,is introduced through inlet conduit 3 into section 4 inwhichflashing or vaporization is caused to occur. Vapors pass fromsection 4 through space 5, are turned through 180 degrees, and passedthrough section 6 in which they are treated with a condensing spray 7causing their condensation to liquid distillate product, In order toprevent intermingling of residual liquid and distillate product a dam 9is provided, residual liquid being withdrawn through conduit 10 anddistillate product being withdrawn through conduit 11. A conduit 8suitably equipped with a guard chamber (not shown) leads to a vacuum jetwhich in the modification described is employed to cause interior ofvessel 1 to be a zone of reduced pressure. In some instances, it isadvantageous to provide the interior surface of the vessel 1, as shownat 12, with a surface which is so machined as to encourage coalescingand rapid draining therefrom of entrained liquid droplets which arecaused to impinge on said surface. Although spray 7 has been describedto be a condensing spray, it

is clearly within the scope of the invention to employ more than onespray, to employ no spray at all relying merely upon radiation coolingto condense the vapors. It is also within the scope of the invention toremove the vapors from vessel 1 and to cause their condensationelsewhere. In any event, it is also within the scope of the invention touse spray 7 as a clean-up spray as more fully described and set forth inabove-mentioned Serial Number 188,604. Still further, when spray 7 isemployed it can be oriented in any desired direction. The positioning ofwithdrawal 10 is not critical as long as it is placed so that residualliquid formed upon flashing and collected at the base of end 12 of thevessel can be accomplished. More than one residual liquid withdrawal oroutlet can be provided.

DESCRIPTION OF FIGURE 3 .over dams 30. Turning around the ends 28 thevapors give up entrained material which falls and collects between .dams26 and 30, and which is withdrawn at 29.

Owing to cooling due to radiation (or by means not shown), somecondensate collects between dams 26 and 30 and it, too, is withdrawnthrough conduits 29. For ease of illustration, the dams 30 have beenshown to lie in a plane with the longitudinal axis of the vessel.However, it is clear that for maximum clean-up of the vapors owing tothe centrifugal force developed as the vapors are turned around the endsof partition 20, the dams 30 can be placed at right angles to a planepassing vertically through the longitudinal axis of the vessel. Suchdams are indicated by dotted lines 35 in Figure 5. Sprays 31 which canbe operated as described in connection with Figure 1, can be employed tocause condensation of distillate product which will collect t0 the farside of dams 30 and which can be withdrawn at 32. When desired tooperate sprays 31 as clean-up sprays substantially at the temperature ofthe vapors passing over dam 30, liquid withdrawn through 32 will consistsubstantially only of the clean-up spray liquid in which event cleancondensate is condensed by means of sprays 33 and withdrawn at 34.Vacuum-producing means, not shown, suitably protected by a guardchamber, are applied to vessel 21 near outlet 34 but, obviously, placedat a point above withdrawal conduit 34 which is placed at or near thebottom of the vessel. The sprays 31 or sprays like sprays 31 can beplaced before or after dams 30 and, indeed, additional dams can beprovided between the withdrawals 32 and withdrawal 34 in order toseparate liquids accumulating on that side of partition 20 into severalportions as desired.

DESCRIPTION OF FIGURE 6 In Figure 6 feed is passed into chamber 40through conduits 41, manifolds 42, and spray heads 43. Vapors aregenerated and passed around the ends of partition 44. In passing aroundthe ends of partition 44, entrained droplets are caused to impingeagainst each other and against ends 45 of vessel 40 and any liquid thusentrained and liquid residue formed in the vessel are withdrawn throughconduits 46. Vapors passing upward and to a point above partition 44 arecondensed employing sprays 47 to which suitable condensing fluid is fedthrough lines 48 and manifold 49. Clean condensate accumulates inpartition 44, which is dished to provide for such collection, and iswithdrawn therefrom through conduit 50. Vessel 40 is advantageouslyconnected to a souce of vacuum which is protected by cold guard spray51.

It will be obvious to one skilled in the art in possession of thisdisclosure that by virtue of the design of the apparatus of my inventionand its operation according to the method of the invention, the pressuredrop from the point of flash to the point of connection with thevacuum-producing means is considerably reduced and, indeed, whereaspressure drops of from 2000 to 2500 microns of mercury have beenexperienced in other forms of apparatus and methods, the only pressuredrop experienced when operating according to the method of thisinvention is that of flow in an open vessel with reversal of flow at atleast one end thereof. In terms of improvement resulting from theinvention, it now appears that the same quantity of distillate, forinstance, gas oil, can be flashed from a feed at 600 F. as heretoforecould be flashed at 680 F. in cases in which baffles placed transverselyof the path of flow have been employed. Thus, it is clear that accordingto the present invention, there is obtained an increased depth of flashat the same temperature or the same depth of flash at a lowertemperature, the advantages of which are readily apparent to one skilledin the art. The herein described apparatus is especially useful for thevacuum flashing of various hydrocarbon oils especially at reducedpressures as in the case of deep flash of residual oils to obtainmaximum distillate product at minimum temperature. Further, theinvention is especially well adapted to partial dehydration, byflashing, of food products such as milk and .fruit juices, vegetableoils, animal oils. and solutions or suspensions of various materials orchemicals especially at reduced pressures.

Reasonable variation and modification are possible within the scope ofthe foregoing disclosure, drawings,

and the appended claims to the invention, the essence of which is thatvapors flashed from a liquid to be separated into a vapor portion and aliquid portion are caused to turn through at least 90 degrees more. orless, there being no substantial quantity of liquid in the .line of flowof said vapors, to cause centrifugal removal of entrained liquidparticles from said vapors and that apparatus essentially comprising ahorizontally placed elongated shell having therein a longitudinalpartition means, said .partition means extending a substantial lengthwithin said vessel and said vessel being provided with an inlet meanscommunicating with the inside of said vessel on one side of saidpartition and an outlet means communicating with the inside of saidvessel on the other side of said partition, thus establishing apassageway through said vessel around at least one end of said partitionmeans within said vessel, have been provided substantially as set forthand described herein.

Referring .now to. Figure 8, a material to be distilled or flashed isfed into vessel 6%} through conduit 61 and, as shown, issprayed againstthe end Wall 62 of said vessel. Vapors generated pass through the vesselturning through an angle ofabout90 degrees, over darn 63, which isadapted to prevent .unflashed residue material "fromfleaving theflashingsection of the vessel, into a condensing section 64- in whichthe vapors are condensed.

'Residue is 'withdrawnfrom the vessel through conduit 65 and condensateis withdrawn from the vessel through conduit 66. A condensing spray 67is employed to cause the desired condensation of the vapors. As thevapors are turned in the vessel entrained non-vaporized materialimpinges by virtue of its acquired momentum upon the inside wall 68 ofthe vessel and flows down said wall and ultimately out from the vesselthrough conduit 65.

X Vacuum flashed topped crude.

I claim:

1. An apparatus for flashing a liquid into a vapor portion and aresidual liquid portion which comprises in combination a substantiallyhorizontal elongated flash distillation vessel, longitudinally disposedinternal partition means within said vessel to provide two compartrnentswithin said vessel communicating with each other at at least one end ofsaid partition means, a liquid inlet for liquid to be flashed at a locussubstantially removed horizontally from said end of said partition meanson one side of said partition means, a vapor condensing means at a locussubstantially removed horizontally from said end of said partition meanson the other side of said partition, means for condensing vapors, meansfor causing accumulation of condensed vapors separately from allnon-vaporized liquid including any entrained liquid, liquid Withdrawalmeans in the bottom of said vessel for withdrawing accumulated residualliquid, and withdrawal means for withdrawing condensed vapors.

2. An apparatus adapted to flash vaporize a liquid material whichcomprises in combination a substantially lation tank, a verticallydisposed substantially axially positioned partition member within saidtank dividing said tank into two compartments communicating at at leastone end of said partition member, liquid inlet means for introducinginto one of said compartments liquid to be flashed, said liquid inletmeans being located at a locus remote from the end of said partitionmeans at which said compartments communicate with each other, a dam atright angles to the axis of said tank across the bottom of thecompartment on the side opposite said inlet means, a liquid withdrawalmeans in the bottom of said tank on each side of said dam, a vaporcondensing means positioned to cause condensation of vapors on the sideof the dam remote from the said inlet means.

3. An apparatus according to claim 2 wherein the tank and partitionmeans are of size relationship such that the communication between saidcompartmentspossesses a cross-sectional area substantially equal to thatof at least one of said compartments, the end of the tank at which thecompartments communicate is dished to provide for smooth flow of vaporsaround the end of said partition means and wherein vacuum-producingmeans to provide a vacuum within said tank are provided on said tank.

4. An apparatus for separating a liquid into a vapor and a residualliquid and to recover a condensed vapor substantially free from anyentrained non-vaporized liquid which comprises in combination asubstantially horizontally disposed elongated flash distillation vessel,a partition means substantially vertically disposed intermediate theends of said vessel dividing the same into two compartments in opencommunication around the ends of said partition means, means forintroducing liquid to be flashed into said vessel on one side of saidpartition means intermediate the ends thereof, a damming means in thebottom of the vessel on each side of said liquid introducing meansintermediate said liquid introducing means and each end of said vesselto accumulate nonvaporized liquid, withdrawal means intermediate theupstream sides of said damming means to withdraw accumulatednon-vaporized liquid from said vessel, additional damming means at thebottom of said vessel at each end of said partition means positionedwithin the compartment to the side of said partition means removed fromsaid liquid introducing means, adapted to retain entrained residuedropping out from the vapor, liquid withdrawal means between each ofsaid first-mentioned damming means and said second-mentioned dammingmeans, condensing means to cause accumulation of condensed vapors beyondeach of said last-mentioned damming means in said compartment remotefrom said liquid introducing mens and means for withdrawing condensedvapors from intermediate the down-stream sides of said lastmentioneddamming means.

5. An apparatus according to claim 4 wherein evacuating means areconnected to said vessel.

6. An apparatus for separating a liquid into a vapor and a residualliquid and to recover a condensed vapor substantially free from anyentrained non-vaporized liquid which comprises a substantiallyhorizontally disposed elongated flash distillation vessel, a dishedpartition member placed substantially horizontally within said vesseldividing the same into upper and lower compartments communicating witheach other at at least one end of said partition member, liquidintroducing means for introducing liquid to be flashed into thecompartment below said partition member, a non-vaporized liquidwithdrawal means in the bottom of said vessel, vapor condensing meansabove said partition member to cause condensation of vapors onto saidpartition member and means connected to said partition member andcommunicating with the outside of said vessel for withdrawing liquidfrom on top of said partition member.

7. An apparatus according to claim 6 wherein the vacuum producing means7 are connected to an upper portion of saidtvessel above said partitionmeans.

8. A substantially horizontally elongated flash distillation vessel,longitudinal vertically disposed partition means shorter than saidvessel disposed within said vessel, said partition means extending asubstantial length within said vessel and an end of said partition beingremoved from an end wall of the vessel, a liquid inlet meanscommunicating with the inside of said vessel on one side of saidpartition removed a substantial horizontal distance from said end ofsaid partition, a liquid flashing section on said one side of saidpartition, a vapor condensing means on the other side of said partition,a liquid outlet means at the bottom of said vessel communicating withthe inside of said vessel on said 'other side of said partition, thusestablishing a passage way through said vessel around said end of saidpartition means within said vessel, said outlet means being removed asubstantial horizontal distance from the said end of said partition.

9. A substantially horizontally elongated flash distillation vessel,longitudinal partition means shorter than said vessel disposed withinsaid vessel, said partition means extending a substantial length withinsaid vessel, an end of 'said partition being removed from an end wall ofthe vessel, a liquid inlet means communicating with the inside of saidvessel on one side of said partition removed a substantial horizontaldistance from said end of said partition, a liquid flashing section onsaid one side of said partition, a vapor condensing means on the otherside of said partition, a liquid outlet means at the bottom of saidvessel communicating with the inside of said vessel on said other sideof said partition, thus establishing a passageway through said vesselaround said end of said partition means within said vessel, said outletmeans being removed a substantial horizontal distance from the said endof said partition.

10. An apparatus for flashing vapors from liquids to produce a condensedvapor product and a residual liquid product, the said condensed vaporproduct being substantially free from entrained liquid, which comprisesin combination a substantially horizontal elongated flash distillationvessel, a longitudinal partition means of length shorter than theinternal length of said vessel extending within said vessel asubstantial length thereof adapted tions, namely, a flashing section anda vapor condensing section, an end of said partition being removed froman end wall of said vessel, a liquid inlet conduitcommunicating withsaid flashing section, a liquid condensate outlet conduit at the bottomof said vessel communicating with said vapor condensing section, and avapor condensing means within said vapor condensing section, said liquidinlet and said liquid outlet conduits being removed a substantialhorizontal distance from the said end of said partition.

11. An apparatus according to claim 10 wherein means are provided foraccumulation of condensed vapors separately from non-vaporized liquidand any entrained liquid and wherein separate withdrawal means at thebottom of the vessel are provided for withdrawing accumulatednon-vaporized liquid and condensed vapors.

References Cited in the file of this patent UNITED STATES PATENTS240,762 Rankin Apr. 26, 1881 374,077 Mathieu Nov. 29, 1887 428,484Hagemann May 20, 1890 907,379 Laurent Dec. 22, 1908 1,407,380 ChenardFeb. 21, 1922 1,757,579 Loomis May 6, 1930 1,982,598 Sieck Nov. 27, 19342,027,395 McVoy Jan. 14, 1936 2,125,325 Youker Aug. 2, 1938 2,177,664Lee Oct. 31, 1939 2,222,575 Schutte Nov. 19, 1940 2,224,685 Kahl Dec.10, 1940 2,358,559 Clemens Sept. 19, 1944 2,443,970 Waddill June 22,1948 2,447,746 Ferris et al Aug. 24, 1948 2,471,893 Pulley May 31, 19492,514,944 Ferris et al July 11, 1950 2,610,142 Lawrence Sept. 9, 1952FOREIGN PATENTS 8,809 Great Britain June 27, 1891 OTHER REFERENCESPerry: Chemical Engineers Handbook, page 514. June 21, 1950. (U. S.Patent Oflice Scientific Library.)

1. AN APPARATUS FOR FLASHING A LIQUID INTO A VAPOR PORTION AND ARESIDUAL LIQUID PORTION WHICH COMPRISES COMBINATION A SUBSTANTIALLYHORIZONTAL ELONGATED FLASH DISTILLATION VESSEL, LONGITUDINALLY DISPOSEDINTERNAL PARTITION MEANS WITHIN SAID VESSEL TO PROVIDE TWO COMPARTMENTSWITHIN SAID VESSEL COMMUNICATING WITH EACH OTHER AT AT LEAST ONE END OFSAID PARTITION MEANS, A LIQUID INLET FOR LIQUID TO BE FLASHED AT A LOCUSSUBSTANTIALLY REMOVED HORIZONTALLY FROM SAID END OF SAID PARTITIONMEANS, A MEANS ON ONE SIDE OF SAID PARTITION MEANS, A VAPOARS, MEANSDENSING MEANS AT A LOCUS SUBSTANTIALLY REMOVED HORIZONTALLY FROM SAIDEND OF SAID PARTITION MEANS ON THE OTHER SIDE OF SAID PARTITION, MEANSFOR CONDENSING VAPORS, MEANS FOR CAUSING ACCUMULATION OF CONDENSEDVAPORS SEPARATELY FROM ALL NON-VAPORIZED LIAUID INCLUDING ANY ENATRAINEDLIQUID, LIQUID WITHDRAWAL MEANS IN THE BOTTOM OF SAID VESSEL FORWITHDRAWING ACCUMULATED RESIDUAL LIQUID, AND WITHDRAWAL MEANS FORWITHDRAWING CONDENSED VAPORS.